WASHINGTON (CNN) --U.S. intelligence sources tell CNN that they have detected recent Iraqi military moves that include placement of Scud missile launch equipment next to mosques and the shipment of explosives into southern Iraq, possibly intended for oil fields.

U.S. intelligence tells CNN:

• The move of launch equipment next to mosques and historic sites is viewed as an effort by Iraq to preserve its launchers from U.S. attack, and is another indicator that Iraq still has Scud missiles. The officials decline to specify the locations of the launch equipment, citing extreme sensitivity, but say the equipment would be a prime target for a U.S. attack.

• Large amounts of conventional explosives are being positioned possibly for detonation of oil fields in southern Iraq, although officials say they cannot confirm that this is Iraq's intent. When asked to describe the amount of explosives involved, one official quantifies it as "railroad cars" full of material.

• There are now two layers of Republican Guard defenses around the Baghdad area. One has been publicly discussed: a Republican Guard unit in place around the outskirts of the city. But U.S. officials are now confirming there is a second layer of Republican Guard defenses "some kilometers" outside the city. That deployment has not been widely acknowledged. It includes new bunkers protecting Iraq military equipment and new firing positions.

• Military aircraft are now defensively dispersed, no longer parked near each other on runways.

• Syria is withdrawing students of Iraqi military academies in advance of any possible U.S. action. U.S. officials say they believe this will be demoralizing to the Iraqi military.

Separately, Gen Tommy Franks, commander of the U.S. Central Command, is scheduled to be in Washington later this week to brief top officials on the progress of war plans.

For more on late developments in the Iraq story, see CNN.com's Iraq Tracker.